It may be the undercard on this year's crowded ballot, but the fight over photo IDs for voters is beginning to attract prominent names and to promise a vigorous debate over the soundness of Minnesota's often-praised election system.

Former Vice President Walter Mondale, a Democrat, joined former Gov. Arne Carlson, a Republican, and former U.S. Rep. Tim Penny, a Democrat-turned third-party member, in strongly denouncing the proposed constitutional amendment on Tuesday. They said it was an unneeded attack on a fair and honest system, a cookie-cutter plan that came from a national campaign stoked by moneyed conservatives.

Meanwhile, the pro-ID side is plugging away at raising questions about fraud and the looseness of a system that allows same-day registration but does not require voters to prove their identity. They are bringing in their own big name, former Vikings' star Matt Birk, to raise money for a billboard campaign and build a kitty for the long battle ahead.

"It comes from the Koch brothers,'' said Carlson, referring to David and Charles Koch, owners of Koch Industries and major funders of a number of conservative causes nationally.

"This is an outside force, coming to Minnesota, telling us how our Constitution ought to be designed," added Carlson.

"Minnesota has the best record of openness, of honesty, of voter participation, of any state in the union," said Mondale. "This is a clean, solid, exemplary state. This constitutional amendment is designed to discourage voting."

The Republican-backed proposal, which is to be submitted to voters in November, would amend the state Constitution to require all voters to show a government-issued photo ID, would create a system of two-step provisional voting for those without proper ID on election day, and would mandate uniform registration requirements for all voters.

Rep. Mary Kiffmeyer, R-Big Lake, a former election judge and secretary of state who has long pushed the amendment, said it is a homegrown movement to improve Minnesota's voting system. "I have no clue what the Koch brothers are," she said.

"It's ludicrous that I'm a blind little follower. ... My position on photo ID was an independent decision of my own, legislation that I worked on in my own way."

No 'bumper sticker campaign'

While the other constitutional amendment proposed for the ballot -- a ban on gay marriage -- attracted nearly $3.7 million in contributions this year, groups supporting or opposing photo ID have thus far reported less than 10 percent of that figure. That suggests photo ID will be less a TV battle of titans and more a series of debates, forums and discussions on the Minnesota election system.

"This is not going to be a bumper-sticker campaign," said Laura Fredrick Wang of the League of Women Voters of Minnesota. "This is a campaign of conversations, taking it out and educating the voters of Minnesota about what this really means."

Mondale, Carlson, Penny and civil rights leader Josie Johnson were named co-chairs of the organization Our Vote Our Future, which will lead an attempt to defeat the amendment. A spokeswoman said the group and its many affiliate organizations will operate phone banks and conduct door-knocking and fundraising efforts for an eventual media campaign.

Two organizations, Protect MyVote.com and Voter ID for MN, are organizing to help pass the amendment, which supporters feel has broad public appeal. Dan McGrath of the group Minnesota Majority, who is helping to organize ProtectMyVote, said his group is sending its decorated vehicle to summertime parades, is polling, questioning focus groups, and will have county coordinators organizing supporters. A spokeswoman said Voter ID for MN is organizing the Matt Birk event to help pay for pro-ID billboards later in the campaign.

Both sides are keeping an eye on the state Supreme Court, which is hearing a petition from the League of Women Voters and others that challenges the amendment's ballot language. Secretary of State Mark Ritchie has asked the court to rule by Aug. 27 at the latest so ballots can be printed.

Battle of politicians

Carlson and Mondale said they became involved after reading about the proposed amendment and the push to get it on the ballot. Carlson blamed the issue on the American Legislative Exchange Council, a group of conservative legislators and business leaders that offers model bills to state legislators. Kiffmeyer is listed as the state chair for ALEC in Minnesota.

"We pride ourselves in two parts of an election,'' Carlson said. "One is high voter turnout. The second is integrity. We've led the nation in both. Now we're subject to a campaign of total disinformation."

Kiffmeyer said she developed her support for the photo ID concept after years as an election judge, secretary of state and legislator, not by ALEC formula. She said that although Minnesota is correctly praised for the way it counts ballots once they are cast, the combination of same-day registration and no requirement of a photo ID creates opportunities for fraud.

"What they're missing is a big part of the election system, and that is, who gets a ballot," she said. "We want the same level of accuracy and integrity in the casting of the ballot, and who casts the ballot, as in the counting and recounting."